Each clue below can be answered with  two-word phrases that have something in common.

1. Run away in fear
2. Way over-eat
3. Collide with
4. Eat as fast as possible
5. Goof off (two answers)
6. Shirk responsibility (as military service)
7. Remain cheerful in the face of adversity
8. Save for later use

Answers:

1. Chicken out
2. Pig out
3. Ram into
4. Wolf down
5. Horse or monkey around
6. Weasel out
7. Bear up
8. Squirrel away

Credit:
A.J. Santora
ON THEIR BESTIAL BEHAVIOR